DTC U1280: Communication Bus Line Error (BUS-OFF)

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2015 Honda Crosstour, 2014 Honda Crosstour, 2013 Honda Crosstour, 2012 Honda Crosstour, and 2011 Honda Accord Crosstour. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

Clear the DTCs with the HDS.
Turn the ignition switch to LOCK (0) and then back to ON (II).
Wait for at least 6 seconds.
Check for DTCs with the HDS.
Is DTC U1280 indicated?

YES -Go to next step.

NO -Intermittent failure, the system is OK at this time. Check for loose or poor connections, or worn/shorted wires. If the connections are good, check the battery condition (see BATTERY TEST ) and the charging system.
Turn the ignition switch to LOCK (0).

Disconnect the appropriate connector at each control unit in the table one at a time. Clear the DTC, then recheck for DTCs after each unit is disconnected.

CONTROL UNIT CHART

Control Unit

Connector

Passenger's MICU

Passenger's under-dash fuse/relay box connector A (38P)

Door multiplex control unit

37P connector

Gauge control module

32P connector

Immobilizer-keyless control unit

7P connector

Audio unit

Connector B (20P)

Climate control unit

Connector B (12P)

Power seat control unit⁽¹⁾

Connector B (40P)

HandsFreeLink control unit⁽²⁾

28P connector

⁽¹⁾

With DPMS

⁽²⁾	With HandsFreeLink

Is DTC U1280 indicated with each individual unit disconnected?

YES -Leave the connectors disconnected, and go to next step.

NO -Go to the input test for the control unit that was disconnected when DTC U1280 did not reset and do all power and ground input tests. If the tests prove OK, replace that unit.

Passenger's MICU input test (see MICU INPUT TEST ).
Door multiplex control unit input test (see POWER WINDOW MASTER SWITCH INPUT TEST ).
Gauge control module input test (see GAUGE CONTROL MODULE INPUT TEST ).
Immobilizer-keyless control unit input test (see IMMOBILIZER-KEYLESS CONTROL UNIT INPUT TEST ).
Climate control unit input test (see CLIMATE CONTROL POWER AND GROUND CIRCUIT TROUBLESHOOTING ).
Power seat control unit input test (see POWER SEAT CONTROL UNIT INPUT TEST/REPLACEMENT )
HandsFreeLink control unit input test (see SYSTEM DESCRIPTION ).

Turn the ignition switch to LOCK (0).
Disconnect driver's under-dash fuse/relay box connector P (20P).
Check for continuity between driver's under-dash fuse/relay box connector P (20P) terminals No. 5 and No. 6.

Fig 1: Checking Continuity Between Driver's Under-Dash Fuse/Relay Box Connector P (20P) Terminals No. 5 And No. 6
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short between the B-CAN wires.

NO -Go to next step.
Check for continuity between body ground and driver's under-dash fuse/relay box connector P (20P) terminals No. 5 and No. 6 individually.

Fig 2: Checking Continuity Between Body Ground And Driver's Under-Dash Fuse/Relay Box Connector P (20P) Terminals No. 5 And No. 6
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short to ground in the wire.

NO -Go to next step.
Turn the ignition switch to ON (II).
Measure the voltage between body ground and driver's under-dash fuse/relay box connector P (20P) terminals No. 5 and No. 6 individually.

Fig 3: Measuring Voltage Between Body Ground And Driver's Under-Dash Fuse/Relay Box Connector P (20P) Terminals No. 5 And No. 6
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there voltage?

YES -Repair a short to power in the wire.

NO -Faulty driver's MICU; replace the driver's under-dash fuse/relay box, USA models (see DRIVER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL AND INSTALLATION ), Canada models (see CANADA MODELS ).